Question

What is the next number in the sequence 625, 25, ____?

Answer 1

Probably the next number is intended to be `5`, but many solutions are possible.

Explanation:

Since `sqrt(625) =25`
and `sqrt(25) = 5`
`5` is a possible answer for the "next number"

However `625 - 600 = 25`
and `25 - 600 = -575`
so `-575` is also a possibility.

Actually, if you are willing to work with more complex transformations, any value could be justified as the "next number".